The disclosure relates to an image forming apparatus and a cartridge that is capable of being used with an image forming apparatus.
There exists image forming apparatuses that form an image by developing an electrostatic latent image on a photosensitive member. For example, Japanese Laid-Open Patent Publication No. 6-208263 discloses an image forming apparatus with a pick-up roller that feeds a sheet to a sheet feed path from a sheet accommodating portion disposed on a lower part of the image forming apparatus. An image is formed on the sheet while the sheet is being fed in the sheet feed path. After image formation, the sheet is discharged onto a discharge tray provided on an upper part of the image forming apparatus.
The image forming apparatus is provided with a cartridge that includes a toner tank. The cartridge is capable of being removed from the image forming apparatus, for example, when an amount of toner remaining in the toner tank becomes small. Toner can thus be replenished by replacing the cartridge.
The image forming apparatus is also provided with a sensor that detects the cartridge. The sensor prevents the image forming operations from operating when the cartridge is not installed in the image forming apparatus. Another sensor that detects whether the sheet has passed is disposed on the sheet feed path. The sensor is used to confirm that a sheet jam (i.e., a paper jam) has not occurred by detecting the sheet at an appropriate timing.